The present invention relates to an electric wheelchair frame and, more particularly, to an electric wheelchair frame for increasing stability and comfort.
Taiwan Utility Patent No. M409966 entitled “LINKAGE TYPE VEHICLE FRAME” discloses a vehicle frame including a frame and two wheel assemblies mounted to two sides of the frame. Each wheel assembly includes a power support having a rod and a power source. The rod includes a first end and a second end. A through-hole is provided between the first end and the second end of the rod. A power source and a driving wheel are mounted to the first end of the rod. A first guiding wheel is mounted to the second end of the rod. Each wheel assembly further includes a connecting rod having a first end and a second end. The first end of the connecting rod includes a fork-shaped structure delimiting a groove and two elongated slots on two sides of the groove. A fixing member extends through the elongated slots. Each elongated slot includes a first end and a second end. The rod of the power support is received in the groove. The fixing member extends through the first through-hole. A second guiding wheel is mounted to the second end of the connecting rod.
Although the first and second guiding wheels of the linkage type vehicle frame can sway relative to the frame to provide a buffering effect, when the driving wheels are moving on a bumpy road surface, a considerable proportion of the vibrations and impact forces is transmitted to the frame and, thus, causes large vibrations of the frame, leading to discomfort to the user sitting in the vehicle. Furthermore, when running on a steep slope, the first guiding wheels are apt to be excessively lifted and cause deviation of the center of gravity of the frame, resulting in the risks of turning over of the linkage type vehicle frame. Furthermore, the power supports and the connecting rods might sway sideways and, thus, result in swaying of the frame and poor stability.
Thus, a need exists for a novel electric wheelchair frame to mitigate and/or obviate the above disadvantages.